Tesco boss responds to discovery of horsemeat in burgers - video

Tesco's technical director, Tim Smith, says his company does not yet know how many products containing horsemeat have been sold in their shops, and an investigation is under way into how it happened. Samples from one of Tesco's burger lines contained 29% horsemeat relative to beef content. Traces of horsemeat have also been found in food products sold by Iceland, Lidl and Aldi